A tennis game is described in a manner peculiar to tennis — scores from zero to three points are described as "love", "fifteen", "thirty", and "forty" respectively. LOVE BOATS(18A. Some cruise ships, informally),FIFTEEN MEN (23A. Start of a song with the cry “Yo-ho-ho”),THIRTYSOMETHING (34A. Ken Olin series about baby boomers),FORTY-NINER(50A. One who hoped things would pan out?) and GAME'S OVER (57A. “You lose!”) constitute the interrelated group of this Wednesday crossword.